Electric welding apparatus



1 H. E. SNODGRASS ELECTRIC WELDING APPARATUS 3 Shuts-Shut 1 Filed my 6, 1920 I all!!! l al JNVEN on. M FM W 79% Muromwzv;

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H. E SNODGRASS ELECTRIC WELDING APPARATUS a sums-sum 2 Filed May 6, 1920 INVENTOR. ME

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' A TTORNEYS Jan. 8 1924.

H. E. SNODGRASS ELECTRIC wwmm APPARATUS Filed May a. 1920 3 Shun-shut I :1 20 if K 3' ff [Z i WITNESS: f7 f7 ff 4% a .77 INVENTOR.

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To alljwhom it may con/cent? 'Bel it 'knownthat I HARLAN- E. SNODL c ase, a citizen of the'United; States, resid ing. at Summit. in the county of Union and State'of New. Jersey; have invented certain new and useful Improvements in Electric Welding A parat is, of which the following reference to the accompanying drawings, in

is a speci cation In accordance with my invention, two

abutting metallic edges are welded together 'b current that is caused to pass from one a utting' edge to the other, and while not [limited thereto, my invention is particularly ap licable to the welding of seamed tubing. ne ofthe features of myinvention' is the provision of a' welding apparatus ofthe character indicated, comprism twocontact piecesengaging'on opposite si es ofthe ap-- or seam between two abutting meta lie ed s, and a transformer comprisinga secon ary independent of the frame of the-apparatus and having pole pieces disposed adjacent'i-to the two contact pieces and electrically connected thereto; the-secondary. thus forming a short path for the secondary with minimum lossestherein.

'Another feature of my invention is the provision of a welding apparatus of. the character indicated, comprising a unitary welding roll provided with two insulated contact discs to which current from. the secondary of the transformer 'is supplied.

' Another feature of my invention 'is'the provision of means for cooling the pole pieces throu h which the current passes. Another eature of my invention is-the provision of a transformer having a seconda loop formed of solid material and electrlcal ly'connected to'the welding conta n tween the pole pieces of the secondary of the transformerand the welding contact' pieces to form a convenient electric connection between the pole pieces and the weldin ieces. a a

' tfil another feature of-my invention is the provision of means for dressing the unitarywelding roll, and a transformer univex-sally adjustable '-in position.- Stillanother feature of my invention is so constructing the transformer that its secondary forms an. annular connection with ing roll;

1ami. Serial no, age-Mel I 'the side ofthe welding roll extendin around and preferably all the'wayaround the sha p Other-features of my invention will apear in the specificationand will he 'particm arlv pointed out in the claims,

My invention will best beunderstood by ing-my invention; Fig. 2 is an end elevation,

partially in sectionpas -.viewed from the le tional elevation showing the unitary weldalong the axis of welding roll-;- Fig. 5 is of Fig. 1; Fig. 3is-a transverse see-- Fig. :4 is a sectional view taken is a section through one of the pole pleces of r the secondary of the transformer; Fig. 6 is a planview of-the transformer and associated parts; Fi 7 is a side elevation illustrating 'the'pos'ition of the dressing tool with respect to the welding roll, and Fig. 8 is a plan view of the dressing'tooland'the associated -means for adjusting'the same.

Like reference characters indicate like" parts throughout the drawings.

Referring, now, to the drawings, 10 are the'leg supports of the apparatus provided with bed-plates 11 and 121on' which the working parts oftheapparatus are mounted, and 113 indicates a frame for the pulling device' and for supporting the finished tubing after .leaving the weldin proper. Standards '14 (see mounted'on t bed-plate. 11 and standards apparatus ig. 2). are- 15 are'mounted on the bed-plate 12, within which are mounted .the' rolls 15 mounted v in front of the welding rolls. and for guiding the tubing thereto. Standards .16 sup port the transformer and associated'parts.

A-shaft 17 has its bearings at 18 in suitable blocks mounted within the standards 14. A roll 19, grooved M19, is mounted on the'shaft 17and cooperates with a welding roll 20 secured on a shaft 21 having its bearings at 22 in blocks 23 which are vertically adjustable for the purpose of mainlco taining the welding mll correctly positioned with respect to the lower roll 19. The healing blocks 23 are pressed upwardly by being limited by screws 25 pwing prings 24, onlyone of which is shown in through the top part of the standards 14 and by which the vertical position of the bearing blocks, and accordin ly the shaft 21, may be adjusted. The sha t 17 is driven by any suitable means, which is illustrated as a sprocket'26 engaged by'a sprocket chain 27 connected to a suitable source of power. A gear 28 is secured on the shaft 17 and en ages a gear 29 on the shaft 21.

eferring, now, more particularly to Figs. 3 and 4, the unitary welding roll 20 comprises two contactpieces 30 and 31 in the form of annular discs which are separated from each other by an insulating member and the heads of the screws preferably en gaging insulating washers 37, in turn, engaging insulating collars 38, angular in cros section, as shown in Fig. 4.'the outwardly extending flanges of which rest in the bottom of the recesses 36, andthe cy lindrical portions 39 of which form sleeves positioned between the screws 34 and the wall of the opening in the disc 31 surroundin the screw;

e welding roll 20 is secured to the shaft 21 b a sleeve 40 of insulating material whic fits within a central 0 ening 41 of the roll 20, and may be secured ereto by screws 42 received in the openings between the sleeve and the. wall of the opening 41. The sleeve 40 is keyed to the shaft 21, as at 43. Each of the discs 30 and 31 is provided on its outer face with an annular recess 44 for a purpose that will later ap er.

I Wlll now describethe trans ormer and associated parts. I have indicated at 45 a frame for supporting the transformer, the

placed back to back at eac frame comprlslng angle-irons 46 extending along the sides of the transformer, as in: dicated in Fig. 6; and end angle-irons 47, two such end angle-irons referably being ll end, with the vertical flanges against each other and riveted or otherwise secured to the angle-irons 46. The transformer is preferabl located above the work, as indicated. T e transformer comprises a laminated core 49, the sheets of which are bound together by clamping bolts 50 which engage clamping irons 51 above thetransformer and angleirons 52 below the transformer, the latter slidably engaging the frame45. The transformer is ad usted in any direction horizontally by screws 53 passingthrough the vertical flanges of the angle-irons 46 and engaging the clamping irons of the transformer, and by screws 54, passing through the flanges of the angle-irons 47, also entransformer may be adjusted in any direction horizontally by properly adjusting the screws.

In accordance with my invention, provision is also made for adjusting the transformer vertically. In the form here illustrated, the frame 45 engages screw-threaded extensions 55 of the standards 16, the frame resting upon nuts 56 immediately beneath the frame, so that by adjusting the position of the nuts, the vertical position of the transformer may be adjusted.

Current is supplied to the primary 57 of the transformer by supply conductors 58 'connected to any suitable source of electrical supply. The secondary of the transformer, which is preferably formed by a single loop of solid material, preferabl comprises a U-shaped member 60, as in icated in Fig. 2, comprising pole pieces 61 and 62, which are provided with central openings, 63 and 64 through which the. shaft 21 passes the pole piece 61 being clamped to the body of the U-shaped member by bolts and nuts, as shown, while the pole piece 62 is pref-- erably provided; with an oil'set portion 65, which is similarly clamped to the U-shaped member 60. Metal washers 67 and 68 are received within the recesses 44 of the two welding members 30 and T31 of the unitary contact roll and form a frictional engagement between the pole pieces 61 and of. the two weldin pieces 30 and The metal washers 67 an 6.8 are preferab y formed of a metal which is harder than that of either the pole pieces or the unitary roll, in order to reduce the friction so far. as ssible. By making the secondary solid, as castin serious losses, which would resu t wit-h a laminated secondary, are obviated. Furthermore, making the secondary of the transformer independent of the apparatus and the provision of the unitary welding roll comprising the two welding members insulated from each other, permits the use of a transformer having a secondary of the described character, having a minimum length and in which the losses are reduced to a minimum.

In accordance with m invention, means are also provided for maintaining a substantially constant pressure between the pole pieces, the washers and the discs of the unitary roll. For this purpose, resilientv washers 69 and 70 are placed against the outer faces of the pole pieces 61 and 62, and a clamping head 71 is adjustably secured on shaft, and the welding rol the outer end ofthe shaft 21, a metal washer 71 referably being interposed between the head and the washer 70, and a metal washer 69' being interposed between the rubber washer 69 and the standard 14. The head 71 is secured in position a inst the washer 71 b a nut 72 and a loclt'm nut 7 3 engaging t e screw-threaded end 4 of the shaft 21. A ball-bearing is referably provided between the nut 72 and the outer face of the head 71, the head 71 being provided with a race 75 in which are placed balls 76. -By the described means, the pressure against the friction discs may be adjusted, and this pressure is maintained substantially constant by the resilient washers 69 and 70, which compensate for any slight variation resulting from the wear of the parts.

Provision is also made for ad'usting the welding roll 20 longitudinally o the shaft 21. For this purpose a sleeve 77 surrounding the shaft 21 engages the insulating sleeve 40', as shown. The outer end of the sleeve .77 is counter-bored, as at 78, and rovided with screw threads which engage t 1e screw threads 79 formed on a hub on the shaft 21 adjacent the collar 80. A flanged sleeve 81 surrounding the -shaft 21 enga es the insulating sleeve 4:0,within the wel ing roll 20 on the opposite side thereof from the sleeve 77, and the outer flanged end of the sleeve 81 is received in a recess in the head 71. Because of the screw-thread engagement of the sleeve 77 with the screw threads 79, the same maybe adjusted longitudinally of the 20 may be given a corresponding adjustment. 7 In the operation of a Welding apparatus of the described character, a large amount of heat is necessarily developed at the welding roll and at the friction discs 67 and 68,

and in accordance with'my invention, provision is made for cooling the pole pieces andthereby keeping the temperature within safe limits; The pole pieces arechambered at 83, as best shown in'Fig- 5. anda partition or septum 85 is formed therein, as indicated. Water is supplied to the chamhere 83 of the pole-pieces byinlet pipes 86 (only one of which isshown in Fig. 1) which are nippled to the pole pieces, as at 87. outlet nipples 88 being connected to the outlet pipe 89. A pipe 90 is also preferably provided, connected to the pipe 89 and havmg a nozzle 91 located above the tubing A as it leaves the welding apparatus. for the purpose of cooling the same. It will be understood that the water entering the chamber 83 is forced around through the chamber in contact with the walls thereof. A tool 92 (see Fig. 1) is preferably provided for smoothing the welded part of the tubing as it leaves the welding apparatus.

A clamp 98. as shown in Fig. Lrn'ga'gcs the end of the tubing and drags the tubfrom ing through the weldingapparatus. This clamping arrangement constitutes no part of my invention and the same need not be described in detail.

I have shown in Fi 7 and 8, at 94 in general, a device for diessing the welding roll. It will be understood that after the weldin operation has continued for some time, t e groove in the welding roll becomes more or less roughened, and it is desirable to dress the roll in order to maintain a satisfacto working surface between the welding r0 1 and the tubing. An arm 95 is ivoted at 96 to a stationary bracket 97. he arm is provided with a vertical openin 98, which 13 preferably cylindrical in orm, within which is received a bar or member 99 provided with a contracted portion 100 which is received within the opening 98 and which is secured in position by a nut or nuts 101 engaging the lower end thereof. A dressing tool 102 is mounted in the member 99 and is secured in position by a set-screw 103. The position of the arm 95 is adjusted toward the welding roll by means of a screw 104 passing through a stationary bracket 105 and engaging the arm 95. The bar or member'99 is provided with openings 106 for the reception of a pinor handle by which the same may be rotated. In order to dress the welding roll, the tool is moved into engagement with the welding roll by means of the adjusting screw 104, and then by rotating the welding roll 20 and graduall rotating the bar 99, the groove in the we ding roll is dressed, it being understood that the center of the member 99 coincides with the center of the groove at the point where the tool is located. The cylindrical part of the roll may be dressed by a hand-held tool.

The adjustment of the transformer is especially advantageous where the diameter of the welding roll is varied, because of the dressing operation, in the manner described, as the welding roll may be kept properly positioned with respect to t e lower roll, and the proper pressure between the welding roll and the tubing maintained. This feature is of importance, as satisfactory welding is dependent on a proper pressure between the welding roll and the tubing.

The operation of the device embodying my invention will readily be understood the foregoing description. The seamed tubing A is fed between the guide rolls 15' to the welding rolls, provision being made for causing the seam of the tubing to come directly beneath the insulating member 32 of the welding roll, so that the two sides of the tube opposite the seam are brought into engagement with the respective contact discs 30 and 31, and the current passing between the butt edges of the tubing adjacent the seamheats the tubing sufficiently to weld the same. After passing from the welding rolls, the tubing is engaged by the roll 92, and the tool 92 scrapes or dresses the welded art of the tubing so that it presents a nished appearance.

Although I have shown various features of my invention, which are set forth at the beginning of this specification and in the claims, in forms which are practicable, I

do not wish to limit myself to these forms,

since I am aware that the ideas embodied therein are susceptible of embodiment in a variety of forms without departing from the rinciple of my invention.

hat I claim and desire to secure by Letters Patent of the United States is:

1. In an apparatus for welding two metallic abutting edges, a unitary welding roll comprising two welding members insulated from each other and secured together, and a transformer whose secondary includes stationary pole pieces having annular surfaces ad acent to and facing the sides. of said welding roll.

2. In an apparatus for welding two metallic abutting edges, a unitary welding roll comprising two welding members insulated from each other and secured together, the welding roll being formed with a groove for the rece tion of tubing to be welded, and a trans ormer having a secondary including stationary pole pieces having annular surfaces adjacent to and facing the sides of said welding roll.

3. In an apparatus for welding two metallic abutting edges, a unitary welding roll comprising two welding members insulated from each other and secured together, a transformer comprising a secondary including a loop formed of solid metal and provided with stationary pole pieces having annular surfaces adjacent to and facing the sides of said welding roll.

4. In an apparatus for welding two metallic abutting edges, welding members for engaging the metal on opposite sides of the seam. a transformer comprising a secondary formed with pole pieces, said pole pieces being provided with chambers, and connections for passing a cooling fluid through said chambers.

In an apparatus for welding two metallic abutting edges, two welding members for engaging .the metal on opposite sides of the seam, a transformer comprising a secondary' loop formed with pole pieces disposed adjacent to said welding members, said pole pieces being formed with chambers, and connections for circulating a cooling fluid through said chambers.

6. In an apparatus for welding two me.- tallic abutting edges, a welding roll comprising two welding members for engaging the metal, on opposite sides of the seam, a

transformer comprising a secondary loop formed with pole pieces disposed adjacent to said welding members, friction members disposed betwsen said le pieces and said welding members, said pole pieces being formed with chambers, and means for passing a ooling fluid through said chambers.

7. In an apparatus for weldin two metallic abutting edges, a welding ro comprising two welding members for engaging the metal on opposite sides of the scam, a transformer comprising a secondary loop formed of solid materlal and having pole pieces dis osed adjacent to said welding members, riction members disposed between said pole pieces and said welding members,

said pole pieces being formed with chambers.

and means for passing a cooling fluid through said chambers.

8. In a tube welding apparatus, a welding roll comprising two welding members for engaging the tubing on opposite sides of the seam, said roll being provided with a groove for receiving the tubing, a transformer having a. secondary including pole pieces disposed adjacent to the respective welding members and electrically connected thereto, and means for dressing the roll, and means for adjusting said roll and said transformer vertically.

9. In an apparatus for welding two metallic abutting edges, a welding roll comprising two welding members for engaging the metal on opposite sides of the seam, a transformer having a secondary including pole pieces disposed adjacent to the respective welding members and electrically connected thereto, and means for adjusting the position of said transformer in any direction to position the pole pieces properly with respect to said welding roll.

'10. In an apparatus for welding two metallic abutting edges, in combination, the rotary welding members, and a transformer the secondary of which is provided with annular pole pieces forming an annular electrical connection with one of said welding members. v

11. In an apparatus for welding two metallic abutting edges, in combination, a rotary welding apparatus, and a trans former the secondary of which is provided with annular pole ieces forming a sliding an nular electrica connection with one of said welding members.

12. In an apparatus for welding two metallic abutting edges, in combination, the rotary welding members, and a transformer the secondary of which is provided with annular pole pieces extending around theaxis of rotation of one of said welding members.

13. In an apparatus for welding two III metallic abutting edges, in combination, the

rotary welding members, a shaft for said membe and a transformer the secondary of whic is provided with annular pole pieces extending around said shaft.

14. In an apparatus for welding two metallic abutting edge gin combination, the rotary welding mem and a transformer the secondary of which extender-round the axis of rotation of said welding members and forms electrical connections respectively with the opposite sides thereof.

15. In an apparatus for welding two metallic abutting ed es, in combination, the rotary welding mem rs, and a transformer the secondary of which is provided with annular pole pieces forming a circular connection respectively with each of said welding members substantially concentric with" said two parts, and a transformer the secondary of which is provided with annular with each of said arts.

HAR E. SNODGRASS.

pole pieces forming an electrical connection 

